Doxycycline for Macaws: Uses, Dosing & Side Effects

This information is for educational purposes only. Never give your pet any medication without your veterinarian's guidance. Dosing, frequency, and safety depend on your pet's specific health profile.

Doxycycline is a tetracycline antibiotic that your vet may prescribe for macaws when a bacterial infection is suspected or confirmed. In birds, it is used extra-label, which means the medication is not specifically labeled for macaws but is commonly used in avian medicine under veterinary supervision.

One of its most important uses in parrots and macaws is treatment of avian chlamydiosis caused by Chlamydia psittaci. This infection can affect the eyes, nose, lungs, liver, and droppings, and it can also spread to people. Because of that, doxycycline is not a medication to start, stop, or adjust on your own.

Doxycycline may be given as an oral liquid, tablet, capsule, compounded suspension, or as a long-acting injection depending on the bird, the diagnosis, and how reliably medication can be given at home. Your vet will choose the form that best fits your macaw's size, temperament, appetite, and overall health.

In macaws, doxycycline is used most often for susceptible bacterial infections, especially psittacosis / avian chlamydiosis. This is a major reason avian vets reach for doxycycline, because treatment usually needs to continue for a full 45 days without interruption to clear the organism through its life cycle.

Your vet may also consider doxycycline for some respiratory infections, sinus disease, conjunctivitis, or other bacterial problems when exam findings, testing, or response history support it. It is not effective against viruses, and it is not the right choice for every bacterial infection.

Because sick birds often hide signs until they are quite ill, your vet may recommend diagnostics before or during treatment. These can include a physical exam, weight check, bloodwork, PCR testing for C. psittaci, Gram stain, culture, or imaging. That helps match the antibiotic plan to the actual problem instead of guessing.

See your vet immediately if your macaw is open-mouth breathing, fluffed and weak, not eating, or showing rapid weight loss. Doxycycline dosing in birds is species-specific and diagnosis-specific, so pet parents should never calculate a dose from dog, cat, or human instructions.

For avian chlamydiosis, Merck lists several avian protocols. A general pet-bird reference dose is 25 mg/kg by mouth twice daily for 45 days, while a species-focused chlamydiosis table lists blue-and-gold macaws and green-winged macaws at 25 mg/kg by mouth every 24 hours. Merck also lists a long-acting injectable option of 75-100 mg/kg IM or SC every 5 days, then weekly for six treatments for chlamydial disease. Your vet will decide which protocol fits your macaw, because formulation, species, tolerance, and blood levels all matter.

Give the medication exactly as directed and finish the full course unless your vet changes the plan. If your macaw spits out doses, vomits, or refuses food after medication, contact your vet before the next dose. Oral doxycycline can interact with dietary calcium, so your vet may adjust supplements or feeding timing during treatment.

Common side effects of doxycycline can include decreased appetite, loose droppings, vomiting or regurgitation, lethargy, and GI upset. Birds on longer courses may also develop yeast overgrowth because antibiotics can disrupt normal gut flora. If your macaw seems less interested in food, quieter than usual, or starts passing abnormal droppings, let your vet know promptly.

Some birds dislike the taste of compounded liquids and may drool, shake the head, or fling medication. That does not always mean a true reaction, but it can still affect how much medicine is actually swallowed. Your vet may be able to change the formulation or route.

More serious concerns include worsening weakness, persistent vomiting, marked anorexia, dehydration, or signs of liver irritation on bloodwork. If your macaw stops eating, loses weight, or seems to be breathing harder, do not wait. Birds can decline quickly, and supportive care may be needed alongside the antibiotic.

Doxycycline can interact with substances that contain calcium, magnesium, aluminum, or iron. In general tetracycline pharmacology, these minerals can bind the drug and reduce absorption, and Merck's bird guidance specifically notes that dietary calcium sources should be reduced if oral doxycycline is used. That matters for macaws receiving calcium supplements, mineral blocks, antacids, or certain fortified hand-feeding products.

Tell your vet about all medications and supplements, including probiotics, liver support products, over-the-counter powders, and anything added to food or water. Even products that seem harmless can change how well the antibiotic works.

Your vet may also use extra caution if your macaw is on other medications processed by the liver or if there is pre-existing liver disease, dehydration, or poor appetite. Do not combine doxycycline with another antibiotic or change the schedule on your own. If a dose is missed, ask your vet or pharmacist what to do next rather than doubling up.